<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>测试1</title>
    <style type="text/css">
        div{
            width: 6.25rem;
            height: 100px;
            border: 1px solid red;
        }

    </style>
</head>
<body>

<button type="button" onclick="f()">哈哈</button>
</body>
</html>
